Patients in intensive care often need to be mechanically ventilated for long periods of time. Mechanical ventilation is delivered through a cuffed tube placed in the trachea. As gas flows to and from the patient, the pressure drop across this tube causes extra work for the patient and causes distortion in lung pressure measurements. We have developed a system to measure the pressure in the lungs using a standard endotracheal tube. We propose to apply this technology to enhance mechanical ventilators and Improve the information used by physicians. We will build a system to measure the tracheal pressure from the endotracheal tube cuff. A device will be built to modify the pressure observed by a mechanical ventilator. We will test this system using two types of ventilators and a mechanical lung simulator. Testing will be done to determine if the modified ventilator correctly compensates for the pressure drop across the endotracheal tube, using various sizes of tubes. The system will also be tested simulating various clinical conditions resulting in obstructed endotracheal tubes. Following phase II, we will manufacture OEM circuit that can be integrated into ICU ventilators. PROPOSED COMMERCIAL APPLICATIONS: The proposed tracheal pressure controller could potentially become part of all ICU ventilators. The enhanced ventilator performance provided by the controller would add approximately $500 in value to the ventilator. There are over 88,000 Intensive Care Units in the US, each equipped with a ventilator. The total US market is thus $44 million. The total world market is about $132 million.